1. Field of the Invention
The invention relates to an apparatus for taking up articles by means of a receiving table, which receiving table is displaceable towards said article. The invention also relates to a method for taking up articles by using such an apparatus.
2. Discussion of the Background of the Invention and Material Information
Devices for taking up articles automatically are preferably used in automated warehouses. In such warehouses various kind of articles can be stored, and an apparatus should be capable of taking up all of these articles quickly and securely, e.g. for transferring them onto a vehicle for the loading and unloading of shelves.
A known prior art apparatus, described in U.S. Pat. No. 5,265,712, comprises a receiving table, which can be displaced towards the article to be taken up. On its front end, this table is provided with rollers, which are driven by a conveyor belt. When they come into contact with the article, the rollers or the conveyor belt, respectively, exert an upward frictional force on the article, which lifts the article at its front end. This lifting movement can be supported by lowering an auxiliary pickup member, from above, onto the article. This auxiliary pickup member exerts a force on the top side of the article which is directed away from the apparatus, thereby supporting the lifting movement by its torque. Once the front end of the article has been lifted, the receiving table is moved into the gap opening below the article. The conveyor is then operated with a velocity that is equal but opposite to the velocity of the receiving table. In this way, the article is loaded onto the receiving table without being displaced horizontally. A similar prior art device is described in U.S. Pat. No. 3,070,241.
The previously described method is not suited for all kinds of articles. Problems occur, e.g. with package-like articles that are comparatively stiff. If such an article is lifted with the method described above, it is tilted about its lower rear edge, facing away from the apparatus. If a plurality of such articles are stored closely behind each other, or if an article is located with its back against a wall, this tilting movement is obstructed because the article comes into contact with the next article or the wall behind it.
Another prior art device for taking up articles is described in German Patent Publication DE 1,907,109. Here, the receiving table is provided with a lever, which is hooked into a recess in the article and pulls the article onto the receiving table. This device is, however, only suited for articles provided with a suitable recess. Furthermore, the articles are also tilted about their lower rear edge, which makes this device unsuitable for taking up articles located closely behind each other.
Prior art European Patent Publication, EP 462 518 and corresponding U.S. Pat. No. 5,238,350 disclose a further device, which is provided with an auxiliary tilting device which is pushed against the article for tilting same. In this way, the article is tilted about its lower rear edge, which-- as mentioned above--makes it impossible to take up articles located closely behind each other.